Electromagnetic Radiation from Electrons Rotating in an Ionized Medium Under the Action of a Uniform Magnetic Field

Abstract

A theory is given for the radiation from a fast electron rotating, under the action of an external magnetic field, in an ionized plasma. It is shown that, although the radiation is emitted predominantly in the extraordinary mode, the ordinary mode is also weakly excited, even in the limiting case in which the density of the background plasma is vanishingly small. At the harmonics of the gyro frequency of the fast electron the power radiated in the ordinary mode is a few per cent. of that radiated in the extraordinary mode. This ratio is independent of v0,' the velocity of the fast electron, as long as V0 is sufficiently small compared with c, the velocity of light. However, at the fundamental gyro frequency the power radiated in the ordinary mode is lower by a factor $$ than that radiated in the extraordinary mode and indeed is significantly smaller than that radiated, in either mode, at the third harmonic.